Stacker



N. CHRISTMAS April 1, 1969 STAOKER lGEAR GEAR ,ROLLER DOl CHAIN DRUM Sheet VARIABLE VOLTAGE CONTROL [MOTGR BELTS ISAND 36 ROLLERS .filed oct. 16. 1967 Fig.

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,arromvgrs April l, 1969 N. CHRISTMAS 3,436,073

STACKER .filed oct. 1e, 19e? sheet Z or 2 /NI/E/VTOR NEWTON CHR/S TMAS BY PENDLETO/V, /VEUMAN SE/BLD WILL/AMS Arron/vars 3,436,073 STACKER Newton Christmas, 912 S. Elm., Mount Prospect, Ill. 60056 Filed Oct. 16, 1967, Ser. No. 675,411 Int. Cl. B65h 29/12 US. Cl. 271--76 8 Claims ABSTRACT F THE DISCLOSURE This disclosure relates to a stacker for stacking successive signatures of printed material as they issue from a web offset press. The stacker incorporates a break-away type release for disengaging the feed belts which normally function to carry the signatures around a turn-around drum. The release mechanism may be set to function when a predetermined tension on the belts is exceeded during a jammed condition, thereby protecting such belts and permitting manual correction of the jammed condition. The stacker is provided with a variable speed drive, which c011- trols the speed of all of the conveying functions of the stacker.

The present invention is particularly adapted for use at the output of a web offset press in which successive signatures issue from the press in shingled relationship. That is, the leading edge of each signature rests on top of the preceding7 signature, and the trailing edge of each signature is beneath the following signature. In this condition, the signatures may be stacked by restraining movement of the forwardmost signature while allowing the following signatures to continue their forward motion until they become vertically aligned with the forwardmost signature.

Stackers of this general description have been known in the prior art but have been subject to a number of deficiencies which are overcome by the stacker of the present invention. Firstly, the condition of the signatures as they issue from the press is not controllable by the stacker mechanism, and, accordingly, there may be a variation in the thickness of the shingled signatures from the optimum value of this dimension for most efiicient operation of the stacker. When the thickness of the shingled signatures exceeds the maximum for which the stacker is designed, a jam occurs which may result in breaking the feed belts of the stacker, necessitating a relatively long shut down, not only of the stacker, but also of the printing press, for the purpose of repairing the feed belts. This diiculty is overcome in the stacker of the present invention by providing means for disabling the feed mechanism of the stacker at a predetermined value of tension on the feed belts selected below that at which damage can occur to the stacker mechanism. The stacker of the present invention is also equipped with a variable speed capability, which permits the speed of the stacker to be matched to any combination of speed and thickness of signatures issuing from the printing press.

It is therefore the principal object of the present invention to provide a stacker adaptable to various conditions of speed and thickness of shingled signatures issuing from a printing press with which the stacker is associated.

Another object of the present invention is to provide a stacker having a variable speed drive.

A further object of the present invention is to provide means for automatically disabling the feed belts of the stacker in response to a condition in which a predetermined tension on the feed belts is exceeded.

These and other objects of the present invention will become manifest upon an examination of the following description and the accompanying drawings in which:

nited States Patent G r3,436,073 Patented Apr. 1, 1969 ICC FIG. l is a functional diagram illustrating the arrangement of some of the major portions of apparatus forming an illustrative embodiment of the present invention;

FIG. 2 is a perspective view of a portion of the apparatus illustrated in FIG. l;

FIG. 3 is a vertical cross section of a portion of the apparatus illustrated in FIG. 2;

FIG. 4 is a plan view of a portion of the apparatus illustrated in FIGS. 1 and 2;

FIG. 5 is an elevation of a portion of the apparatus illustrated in FIG. 4; and

FIG. 6 is a functional block diagram of the variable speed drive apparatus.

Referring now to FIG. 1, a belt 10 supports a plurality of shingled signatures 12 issuing from a web offset printing press (not shown). The belt 10 passes around a roller 14 supported for rotation on a shaft 15 in fixed relationship to the press. The belt 10 is driven by the drive mechanism of the printing press, and supports the signatures 12 on its top surface, moving rectilinearly along the downwardly sloping plane defined by the top `surface of the belt 10 toward the roller 14. The belt 10, although illustrated in FIG. 1 as being a single belt, is preferably a plurality of narrow strips of web material spaced apart longitudinally along the roller 14. The spaces between successive strips allow for the passage through the plane of the belt 10 of a plurality of strips forming another belt 16. The belt 10 is conducted around the roller 14 in the direction of the arrows illustrated in FIG. 1.

The belt 16 is formed by a plurality of spaced apart strips 16a and 16b (FIG. 2) similar in construction to those making up the belt 10, and advances in the direction indicated by the arrows in FIG. 1 about a roller 18, mounted for rotation on a shaft 19 disposed below the signatures 12 supported on the belt 10. From the roller 18, the strips 16a and 16b pass upwardly between the` strips forming the belt 10, and proceed around a drum 20 supported for rotation on a shaft 22. The belt 16 passes around slightly less than half of the drum 20 and proceeds from there to a roller 24 supported for rotation on a shaft 26. After passing around the roller 24, the belt 16 proceeds to a roller 28, supported for rotation on a shaft 30, and then proceeds downwardly around a roller 32 and from there returns to the roller 18, passing again through the spaces between successive strips forming the belt 10 in the process. The roller 32 is supported for rotation on a shaft 34.

As above described, the belt 16 is arranged to pass around the drum 20, which will hereinafter be referred to as a turn-around drum, and is maintained in its relationship to the turn-around drum 20 by virtue of the rollers 18, 24, 28 and 32. A further roller 33, mounted for rotation on a shaft 35, is provided near the bottom of the drum 20 to urge the belt into contact with the drum. By virtue of the strips -16a and 16b, and especially their position relative to the strips forming the belt 10, the signatures 12 issuing from the printing press are transferred from the belt 10 to the belt 16 at the location where the two belts intersect, as viewed in FIG. 1, and are thereafter carried upwardly by the belt 16 toward the turn-around drum 20. Upon reaching the turn-around drum 20, the signatures 12 are compressed between the belts 16 and the turn-around drum 20, and by the roller 33, and are then turned with the drum 20 until the top of the drum 20 is reached, where the belt 16 leaves the drum 20.

A lthird belt 36, formed of a pair of strips 36a and 36b, similar to the belts 10 and 16, passes around the drum 20, the strips 36a and 36b being spaced outwardly from the strips 16a and 16b of the belt 16. The belt 36 moves in the direction of the arrows illustrated in FIG. 1 and, in addition to passing around the turnaround drum 20, also passes around rollers 38 and 40 supported for rot-ation, respectively, on shafts 42 and 44.

When the signatures 12 reach the top of the turnaround drum 20, they are held with the belt 36 interposed between the signatures 12 and the drum 20, and with the belt 16 over the signatures y12. The signatures then travel rightwardly as viewed in FIG.` l, compressed between belts 16 and 36.

When the roller 24 is reached, the belt 16 passes upwardly around the roller 124 and leaves the sign-atures 12. However, before each signature passes out of contact with the belt 16, its leading edge is inserted into the nip between a feed roller 46, mounted for rotation on a shaft 50, and a stacking plate 48. The stacking plate 48 is fixed in position, and the belt 36 passes over the stacking plate 48 parallel thereto to reach the roller 38.

The feed roller 46 is driven by the drive means in a direction such as to feed successive signatures 12 along the stacking plate 48 toward alignment with a stack 52, resting on the stacking plate 48.

As each signature reaches the feed roller 46, the pressure between the roller 46 and the stacking plate 48 compresses each signature individually thereby to remove any air 'which may have been entrapped among the pages of the signature. Each signature is thereby rendered as fiat as possible while passing the feed roller 46.

A stop plate S4 is fixed to the stacking plate 48 at the rear thereof, and is provided with apertures 56 for passing the strips 36a and 36b. The leading edges of the successive signatures 12 contact the surface of the stop plate 54 and are thereby prevented from traveling further with the belt 36 as it proceeds through the apertures 56 and around the roller 38.

As each signature reaches the stop plate 54, it is added I to the stack 52 at the bottom thereof, and the result is that the stack S2 gradually grows upwardly. The uppermost signatures in the stack 52 may be removed manually or otherwise without affecting the operation of the stacker.

The entire apparatus of the stacker of the present invention may be disposed directly above the output belt from the printing press, so that the combination of printing press and stacker requires no more floor space than would be required by the printing press alone, with its output belt. This saving of space is partly accomplished by means of the turn-around drum 20, which permits the stacking plate 48 to be positioned on the side of the drum nearer the printing press, rather than on the opposite side.

Both the belts 16 and 36 proceed around the turnaround drum 20, and may be driven by the drum, thereby avoiding the need for separate drive means for the two belts. The shaft Z2 is provided with a gear 58 by which the turn-around drum 20 and both of the belts 16 and 36 are driven in synchronism. The feed roller 46 is driven (FIGS. 4 and 5) lby means of a sprocket 47 and a chain 49. The chain 49 is mechanically coupled to the gear S8 via a linkage including another sprocket S1, so the peripheral speed of the roller 46 is directly related to the speed of translation of the belts 16 and 36. The sprocket 51 is spaced generally horizontally from the feed roller 46 so that it may move generally vertically to accommodate varying thicknesses of signatures. For this purpose the feed roller 46 is supported at its ends in brackets 53 which slide generally vertically in guide grooves 55 cut into the side walls 57 and 59 of the. frame of the machine. The interconnection between the sprocket 51 and. the gear 58 is preferably made by means of a further sprocket and chain connection to the shaft 34, which is turned by movement of the belt 16. The particular manner of connection, however, is not shown as it forms no part of the present invention. The gear ratios and/or the relative number of sprocket teeth is such as to give the required ratio of tangential velocity of the roller 46 to the tangential velocity of the drum 20, the latter being the same as the speed of the belts 16 and 36. It has been found that a slightly greater tangential speed is desirable for the feed roller 46, to break the static friction between successive signatures, and propel each signature forcefully into registry with the stack 52.

A DC motor 65 (shown diagrammatically in FIG. 6) has a gear -61 engaging the gear 58 so that the entire assembly is driven from the motor, via its several interconnecting assemblies. The power circuit of the motor is provided with a speed regulating device `63 which is a variable voltage control and may conveniently employ one of the silicon-controlled rectifier circuits, well known in the art, for controlling the speed of a DC motor. By adjusting the speed of the motor 65, the velocity of bot-h the belts 16 and 36, and the identical tangential velocity of the turn-around roller 20, in addition to the proportional speed of the feed roller 46, may be controlled to any desired value, thereby to accommodate any speed of the feed belt 10, or thickness of the signatures 12 supported on the belt 10. Higher speeds of the feed belt 10, or greater thickness of the signatures 12 (occasioned, for example, by the signatures 12 being spaced closer together along the belt 10) may be accommodated by increasing the speed of the motor connected to the turn-around drum 20 via the gear 58, so that more rapid arrival of the signatures 12 at the intersection of the belt 10 and 16 may be translated into a constant spacing between the leading edges of successive signatures.

The breakaway release feautre of the present invention will now be described, specifically with reference to FIGS. l and 2.

Referring first to FIG. l, most of the parts of the stacker there illustrated are mounted in fixed relationship to the frame, which has the side walls 57 and 59 (FIG. 4). This includes the shaft 22 upon which is mounted the drum 20, and the shafts 14, 34 and 42 which support various rollers. The shafts 35 and 44, which support the rollers 33 and 38, respectively, are slidable relative to the frame, and are urged into operative position by springs 67 and 69, respectively. The arrangement is similar to that illustrated in FIG. 5 relative to the shaft 46, which is urged toward operative position by the spring 71. The remote ends of each of the springs is xed to the frame. The shafts 26 and 30 are not fixed relative to the frame of the machine, but instead are rendered adjustable thereto by virtue of being mounted on a mechanical linkage including a lower arm 60 composed of members 64 and 66 and a forward arm 62 composed of members 72 and 74 (FIG. 2). The mem-bers 64 and 66 are interconnected by means of rods 68 and 70, which function to hold the members 64 and 66 rigid with respect to each other. The lower ends of the members 64 and 66 are pivotally supported on the shaft 34, which is one of those fixed in relationship to the frame. The shaft 30 is supported between the upper ends of the members 64 and 66, and the forward arm 62 is rotatably mounted on the shaft 30. The members 72 and 74 of the forward arm 62 both have an aperture at their rearward ends for receiving the shaft 30, and are rigidly connected at its forward end to the shaft 26. The roller 24 preferably comprises a pair of pulleys 24a and 2411 disposed on the shaft 26, and the roller 28 comprises a pair of pulleys 28a and 28h disposed on the shaft 30. Similarly, the roller 32 comprises pulleys 32a and 321) on the shaft 34. Each of the aforementioned pulleys accommodate one of the strips of which the belt 16 is formed.

With the mechanism as thus far described, it will be apparent that the lower arm 60 may be swung rearwardly away from the turn-around drum 20, and the forward arm 62 may be swung downwardly, thereby permitting the strips 16a and 16b to loosen in relation to the turnaround drum 20. This is in fact what occurs when the release mechanism has been triggered in response t0 greater than a predetermined amount of tension on the belt 16.

The release mechanism incorporates a portion of the side walls 57 and 59 of the frame, and both ends of the shaft 30, one end of which is illustrated in FIG. 3.

The ends of the shaft 30 are each provided with a depression 76 which is concentric with the axis of the shaft 30. As the mechanism at both ends of the shaft 30 is identical, only one end will be described. A portion of the frame 57 adjacent one end of the shaft 30 is provided with an aperture into which is inserted a plug 80, held in place by a C ring 78 disposed in a peripheral groove in the plug 80. The plug 80 is provided with an internal circular bore accommodating a detent member 82, a spring 84, and a closure plug 86. The closure plug 86 has a shaft threadably engaged with threads formed on the interior surface of the bore and the spring 84 is disposed between the plug 86 and the detent member 82, thereby urging the forward portion of the detent member 82 through an opening 88 in the plug 80 and into contact with the depression 76 in the shaft 30. The position of the plug 86 may be Varied by manually screwing it inwardly or outwardly, by means of a knurled wheel at the outer end of the plug 86. A specilic amount of force is required to dislodge the detent member 82 from its cooperative relationship with the depression 76 in the end of the shaft 30, and the magnitude of this force may be readily adjusted `by screwing the plug 86 inwardly or outwardly, thereby adjusting the compression of the spring 86. By this means, the arms 60 and 62 are maintained in the position illustrated in the drawings during normal operation of the stacker.

When a jamming condition occurs, wherein a greater than normal thickness of signatures attempts to pass around the turn-around drum between the belts 16 and 36, the tension on the belt 16 is considerably increased, the belt 16 attempting to stretch about the greater thickness of the signatures. The increased tension in the portion of the belt 16 extending between the turnaround drum 20 and the roller 24 produces a force on the forward arm 62, urging the same backwardly, away from the turn-around drum 20. When this force is suiiicient to dislodge the detent member 82 from cooperative relationship with the depression 76, the lower arm 60 is free to swing away from the turn-around drum 20, and the forward arm 62 is free to travel rearwardly with the lower arm 60, thereby shortening the path about which the belt 16 must travel, reducing the tension on the belt 16, and increasing the space between the belt 16 and the turn-around drum 20. This increased space accommodates the greater thickness of signatures, and also reduces the friction between the signatures 12 and the belts 16 and 36, to permit manual removal of the signatures from this portion of the stacker if necessary.

A stop means (not shown) secured to the frame is positioned to block movement of the lower arm 60 backward so far that the strips 16a and 16b are likely to become dislocated from the pulleys 24a, 24b, 28a and 28h. When the jammed condition is corrected, the lower arm 60 is simply pushed forward manually until the detents again become engaged.

With the arrangement illustrated in the drawings, the forward arm 62 extends above the drum 20 and is free to pivot about the shaft 28. The weight of the arm 62 forces it downwardly, and tends to increase the length of the path traversed by the belt 32 by increasing the length of contact between the belt 16 and the drum 20. By this means the appropriate operating tension is maintained on the belt 16 without the use of any resilient means such as the springs 67 and 69.

What is claimed is:

1. In a stacker for stacking a series of relatively flat articles in shingled condition, the combination comprising conveyor means for supporting said articles, a turnaround drum for conveying said articles from said conveyor means around a turn of about a half-circle, means for `receiving said articles from said drum and orientin-g them into an orderly arrangement, and selectively releasable means for urging said articles into juxtaposition with said drum during said turn, said last named means including a belt, support means for supporting said belt to entrap said articles between said drum and said belt, detent means Afor holding said support means in fixed relationship to said drum, and presettable means for causing said detent to release when the tension in said belt exceeds a predetermined value.

2. Apparatus according to claim 1, including drive means for rotating said drlum and means for selectively adjusting the speed of said drive means.

3. Apparatus according to claim 1, wherein said support means comprises a shaft fixed in position relative to said drum and parallel to the axis thereof, a rst arm supported for rotation on said shaft, and a tirst roller for supporting said belt, said roller being mounted on said arm, said roller pivoting with said arm about said shaft away from said drum when said detent releases.

4. Apparatus according to claim 3, including a second arm connected to said first arm to pivot coaxially with said first roller, and a second roller for supporting said belt, said second roller being mounted on said second arm, said second arm being movable away from said drum with said first arm when said detent releases.

5. Apparatus according to claim 4, wherein said drum is disposed with its axis horizontal and with the beginning and end of said turn being generally horizontal, said `detent means holds said iirst arm in fixed relationship relative to said frame and allows said second arm to pivot freely about said first arm, and said second arm is disposed above the center portion of said drum, whereby downward movement of said second roller lengthens the -path of said belt about said drum, as supported by said iirst and second rollers, whereby the weight of said second arm regulates the tension on said belt while said detent is in its engaged condition.

6. Apparatus according to claim 1, including a frame for supporting said drum, said detent means comprising a. depression on said support means and a detent member on said frame engageable with said depression, and said presettable means comprises a spring for urging Said detent member into engaging relation with said depression, and manually manipulatable means for adjusting the force between said spring and said detent member.

7. Apparatus according to claim 1, including a plurality of belt strips forming an input belt for presenting said articles in seriatim, said conveying means comprising a plurality of belt strips forming a conveyor belt, said conveyor belt intersecting with said input belt to receive said articles from said input belt.

f8. Apparatus according to claim 1, wherein said means for receiving and orienting said articles comprises a generally horizontal stacker plate, an end plate secured to said stacker plate and adapted to dene one side of a stack formed with said articles overlying each other in a generally vertical pile, a feed roller supported above said stacker plate and in generally vertical sliding relationship relative to said stacker plate, means urging said feed roller downwardly relative to said stacker plate, and means for driving said feed roller at a slightly higher tangential velocity than said drum.

References Cited UNITED STATES PATENTS 1,106,222 8/ 1914 Johnson 221-243 3,266,799 8/ 1966 Ingalls 271--76 FOREIGN PATENTS 1,232,986 1/1967 Germany.

RICHARD E. AEGERTER, Primary Examiner.

Dedication 3,436,073.-New150n Oil,

f'zstman, Mount Prospect, Ill. STACKER. Patent dated Apr. 1, 1969. Dedication led Jan. 14, 1974, by the assignee, Industrial Design o Engineering, Inc.

e Public the en tire term of said patent. [Oj'cz'al Gazette Marck IZ, 1.974.] 

